Open Versus Endovascular Repair of Abdominal Aortic Aneurysm

The NEJM published the long-term results of the OVER study of open repair (OR) versus endovascular aneurysm repair (EVAR) of abdominal aortic aneurysm (AAA) on May 30.

The OVER study demonstrated similar long-term overall survival between patients undergoing EVAR and OR. These results were not consistent with the findings of worse performance of EVAR with respect to long-term survival that were seen in two studies conducted in Europe.

In OVER, patients with asymptomatic AAA were randomly assigned to either EVAR or OR for aneurysm treatment and were followed for up to 14 years. This study enrolled 881 patients who were candidates for either procedure, with 444 assigned to EVAR and 437 to OR. The primary outcome was all-cause mortality. Although elective EVAR of AAA has shown lower perioperative mortality than OR, this survival advantage was not seen after 4 years.

Imporant trends include, although none were signficant:

• 302 patients (68%) in the EVAR group and 306 patients (70%) in the OR group died (hazard ratio [HR], 0.96; 95% confidence interval [CI], 0.82–1.13).
• In the first 4 years of follow-up, overall survival appeared to be higher with EVAR versus OR.
• In year 4 through year 8, overall survival was higher in the OR group.
• After 8 years, overall survival was higher in the EVAR group (HR for death, 0.94; 95% CI, 0.74–1.18).

Additional findings:

• There were 12 aneurysm-related deaths (2.7%) in the EVAR group and 16 (3.7%) in the OR group (between-group difference, -1.0 percentage point; 95% CI, -3.3–1.4) with most deaths occurring in the perioperative period.
• Aneurysm rupture occurred in seven patients (1.6%) with EVAR, and rupture of a thoracic aneurysm occurred in one patient (0.2%) with OR (between-group difference, 1.3 percentage points; 95% CI, 0.1–2.6).
• Death from chronic obstructive lung disease was approximately 50% more common in OR patients than EVAR patients (8.2% vs 5.4%) with a between-group difference of -2.8 percentage points (95% CI, -6.2–0.5).
• More patients in the EVAR group underwent secondary procedures.